The present invention relates to a specified neutron detector with a scintillator, and a one-dimensional or a two-dimensional neutron image detector which uses the neutron detector.
As the neutron detector which does not need the position information, 3He gas proportional counter has been chiefly used so far. The reason is that the structure is simple, the neutron detection efficiency is high, and the background of gamma ray sensitivity is low. As for the neutron detector with a scintillator, 6Li glass scintillator or a small neutron detector where a photo multiplier is arranged directly behind ZnS/6LiF translucent neutron scintillator has been used as a neutron monitor or an experimental detector.
In addition, as for the neutron image detector used for the neutron scattering experiment which uses a neutron source etc. with nuclear reactor/particle accelerator, a detection system where many position-sensitivity 3He gas proportional counters are arranged or 3He gas multi-wire two dimension neutron detector, etc. have been used so far. Moreover, as for the neutron image detector with a scintillator, the detector which detects the one-dimensional or the two-dimensional neutron image where the incidence position of fluorescence emitted from 6Li glass scintillator or ZnS/6LiF translucent neutron scintillator is coded by using the optical fiber or the wave length shift fiber and detected by a photo multiplier has been used so far.
In addition, a high-speed neutron detector has been developed, in which a transparent plastic scintillator or a transparent liquid scintillator is contained within a circular detector housing, the signals output from photo multipliers arranged on both sides are processed and measured at a high time resolution, and the incidence position of the fast neutron is measured based on the arrival time difference to the photo multipliers by utilizing the very short life time of fluorescent. Moreover, high-speed neutron/gamma discrimination is performed by utilizing the different rise time between the fast neutron and the gamma ray, because the gamma ray sensitivity is high in a plastic scintillator or a liquid scintillator.    [Non-patent Literature 1] Nucl. Inst. And Meth. 73 (1969)225-227    [Non-patent Literature 2] Nucl. Inst. And Meth. 185 (1981)165-174    [Non-patent Literature 3] Nucl. Inst. And Meth. 214 (1983)401-413    [Non-patent Literature 4] Nucl. Inst. And Meth. A372 (1996)246-252    [Non-patent Literature 5] Nucl. Inst. And Meth. A477 (2002)373-377